The material, as received, must be dry and not contain more than 3% maximum free zinc, 1% maximum free magnesium, and 1.5% maximum free iron and stainless. Not to contain more than a total 5% maximum of non-metallics, of which no more than 1% shall be rubber and plastics. To be free of excessively oxidized material, airbag cannisters, or any sealed or pressurized items. Any variation to be sold by special arrangement between buyer and seller.